The present invention relates to a method of opening bales of fiber, wherein a gripper detaches one layer of fibers at a time from the bale from above and then moves upwards, and an apparatus for carrying out the method.
It is known to detach fiber material from bales of fiber layer-by-layer by means of a gripping device with a gripper arm movable in the vertical direction (U.S. Pat. No. 3,443,285). The gripper arm has gripper fingers disposed in pairs which can be closed and opened like pincers, penetrate into a bale when the gripper arm is lowered onto this, and remove a layer of fiber during the upward movement of the gripper arm. Depending on the point of action of the gripper fingers on the bale and the pressing of the bale, there is the possibility that even with a small opening width of the gripper fingers, a layer of fibers reaching over the whole bale may be detached which then hangs down from the gripper arm as a web of fiber during the upward movement. This is undesirable, particularly when an amount corresponding to a specific mixing proportion has to be detached from bales of fiber of different origin by means of the gripping device (DE-OS 1.685.596). In this case, if such a large amount of fiber is detached shortly before the predetermined mixing proportion is reached, then the mixing proportion is exceeded and the mixing is inaccurate.